package lxs.tool.liberator.common.utils;

import com.qiniu.util.Base64;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;
import java.nio.charset.StandardCharsets;

public class DES {

    public static String encrypt(String message, String key) throws Exception {
        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
        DESKeySpec desKeySpec = new DESKeySpec(key.getBytes(StandardCharsets.UTF_8));
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
        IvParameterSpec iv = new IvParameterSpec(key.getBytes(StandardCharsets.UTF_8));
        cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);
        return encodeBase64(cipher.doFinal(message.getBytes(StandardCharsets.UTF_8)));
    }

    public static String decrypt(String message, String key) throws Exception {
        byte[] bytesrc = decodeBase64(message);//convertHexString(message);
        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
        DESKeySpec desKeySpec = new DESKeySpec(key.getBytes(StandardCharsets.UTF_8));
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
        IvParameterSpec iv = new IvParameterSpec(key.getBytes(StandardCharsets.UTF_8));
        cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
        byte[] retByte = cipher.doFinal(bytesrc);
        return new String(retByte);
    }

    public static byte[] convertHexString(String ss) {
        byte[] digest = new byte[ss.length() / 2];
        for (int i = 0; i < digest.length; i++) {
            String byteString = ss.substring(2 * i, 2 * i + 2);
            int byteValue = Integer.parseInt(byteString, 16);
            digest[i] = (byte) byteValue;
        }

        return digest;
    }

    public static String toHexString(byte[] b) {
        StringBuilder hexString = new StringBuilder();
        for (byte value : b) {
            String plainText = Integer.toHexString(0xff & value);
            if (plainText.length() < 2)
                plainText = "0" + plainText;
            hexString.append(plainText);
        }

        return hexString.toString();
    }


    public static String encodeBase64(byte[] b) {
        return Base64.encodeToString(b, Base64.DEFAULT);
    }

    public static byte[] decodeBase64(String base64String) {
        return Base64.decode(base64String, Base64.DEFAULT);
    }
}
